The present invention relates to a rotating disk storage device and, more particularly, to a rotating disk storage device of the airtightly enclosed type that has a gas-circulation structure suitable for use in cooling the device and in eliminating dust therefrom.
In general, typical rotating disk storage devices such as magnetic disk device have structures which enable elimination of dust from the interior of the devices and cooling of drive systems therein. Japanese Patent Unexamined Publication No. 8692/1980 (U.S. Pat. No. 4,190,870) discloses such a structure having a forced-air supply system in which rotating disks such as magnetic disks surrounded by a shroud as well as an access mechanism of the rotating disks are airtightly enclosed by a cover, with clean air being supplied from the exterior into the cover. Japanese Patent Unexamined Publication No. 200480/1983 discloses an inner circulation system utilizing the flow of air circulated by the rotation of the rotating disks in the device.
The above-mentioned forced-air supply system involves various disadvantages. For example, it is likely that dust or moisture may enter from the exterior and that an increase in cost and a decrease in space storage density may arise because installation of a blower requires a space and expenses. To overcome these disadvantages, the aforesaid airtightly enclosed inner circulation system adopts a structure in which the entire mechanism is accommodated in airtight means with no gas being supplied from the exterior. In the inner circulation system, however, gas is likely to flow from the upstream side of a transducer support inserted into the gaps between the adjacent disks into a drive-mechanism housing constituting one part of the airtight enclosure, and this flow of gas, in turn, reverses from the downstream side of the transducer support to a rotating-disk housing constituting the other part of the airtight enclosure. As a result, dust generated from drive means, in particular, guide means and a coil, may enter the rotating-disk housing and flow into the gaps between the rotating disks and the corresponding transducers, thus resulting in crash accidents. Where a filter for filtering gas is provided in the drive-mechanism housing so as to circulate clean air within the rotating-disk housing, there is a problem in that the level of pressure in the drive-mechanism housing increases owing to pressure loss at the filter and thus amplifies the aforesaid reverse flow.